class_docstr: Test data request different implementations
docstr: Raise an error when a key has not been given
          
docstr_tok: ["Raise","an","error","when","a","key","has","not","been","given"]
code: def test_key_none(self):
      """Raise an error when a key has not been given"""
      try:
          AlphaVantage()
          self.fail(msg="A None api key must raise an error")
      except ValueError:
          self.assertTrue(True)
  
imports: from ..alpha_vantage.alphavantage import AlphaVantage
  from ..alpha_vantage.timeseries import TimeSeries
  from ..alpha_vantage.techindicators import TechIndicators
  from ..alpha_vantage.cryptocurrencies import CryptoCurrencies
  from ..alpha_vantage.foreignexchange import ForeignExchange
  from pandas import DataFrame
  import os
  import unittest
  import timeit
  import time
label_desc: Use image node_id 3 for calling the TestAlphaVantage obj's underlying member method code with example usage: obj.test_key_none() without return types